Visible Spectrophotometric Estimation of Emtricitabine in Pharmaceutical Formulations

Three simple, accurate, rapid and sensitive methods (A, B and C) have been developed for the estimation of Emtricitabine in its pharmaceutical dosage form. The Method A is based on the formation of orange red colored chromogen, due to reaction of Emtricitabine with p-Dimethyl amino Cinnamaldehyde (PDAC) reagent in the presence of methanol, which exhibits λ _max at 538 nm. Method B is based on the reaction of Emtricitabine with 3-methyl-2-benzothiazolinone hydrazone (MBTH) in the presence of Cerric ammonium sulphate to form a bluish green colored chromogen, which shows maximum absorbance at 635 nm. The Method C is based on the formation of reddish brown colored chromogen with Mordant Black Dye in the presence of Phthalate buffer, which shows absorption maximum at 543 nm. The absorbance-concentration plot is linear over the range of 1–10 μg/mL for Method A, 2–18 μg/mL for Method B and 10–90 μg/mL for Method C. Results of analysis for all the methods were validated statistically and by recovery studies. Literature survey reveals only HPLC methods deals with biological fluids and in fixed pharmaceutical dosage forms. The proposed methods are economical and sensitive for the estimation of Emtricitabine in bulk drug and in its formulations.